CN103676113B

CN103676113B - Zoom lens

Info

Publication number: CN103676113B
Application number: CN201310381566.9A
Authority: CN
Inventors: 未来
Original assignee: Tamron Co Ltd
Current assignee: Tamron Co Ltd
Priority date: 2012-09-11
Filing date: 2013-08-28
Publication date: 2016-01-13
Anticipated expiration: 2033-08-28
Also published as: JP2014056056A; CN103676113A

Abstract

The invention provides a kind of zoom lens of small-sized, light weight, it can obtain the image become clear in full zoom territory, and by effectively correcting all aberrations throughout full zoom territory, maintaining high optical property, possessing the resolution of the solid-state imager can tackling high pixel.These zoom lens are configured with the first lens group (G with positive light coke in turn from object side ₁₁), there is the second lens group (G of negative power ₁₂), there is the 3rd lens group (G of positive light coke ₁₃), there is the 4th lens group (G of positive light coke ₁₄), there is the 5th lens group (G of negative power ₁₅) and form.5th lens group (G ₁₅) be configured with negative lens (L in turn from object side ₁₅₁) (the first lens) and be formed with aspheric positive lens (L on two sides ₁₅₂) (the second lens) these 2 simple lenses and forming.And, by meeting defined terms, large aperture ratioization and high resolving power can be made to exist side by side.

Description

Zoom lens

Technical field

To the present invention relates in the camera being equipped with solid-state imager, particularly CCTV camera be suitable for small-sized, the zoom lens of light weight.

Background technology

As the widely used zoom lens of CCTV camera, have from object side configure in turn have positive and negative, just, each lens group of positive and negative focal power and the 5 groups of zoom lens (embodiment 5, patent documentation 2 for example, referring to patent documentation 1) formed.

In these zoom lens, all by the first lens group, the 3rd lens group and the 5th lens group are fixed, and make the second lens group move along a direction and carry out zoom.In addition, by making the 4th lens group move towards the direction along optical axis, thus carry out the correction that changes with the image planes of zoom and focusing.Further, the zoom ratio of the zoom lens described in embodiment 5 of patent documentation 1 is about 3.2 times, and F number (Fnumber) is about 2.0 ~ 3.2.The zoom ratio of the zoom lens described in patent documentation 2 is about 5 times, and F number is about 2.0 ~ 2.4.

[look-ahead technique document]

[patent documentation]

[patent documentation 1] JP 2009-237400 publication

[patent documentation 2] JP 2002-365539 publication

, the zoom lens that the video camera as CCTV camera, particularly traffic monitoring carries, are contemplated to be and also can carry out at night and dim place the large aperture zoom lens that monitor well.And, the high pixelation of solid-state imager (CCD and CMOS etc.) advances rapidly in recent years, requires the high-resolution zoom lens possessing the solid-state imager (can confirm more than 3,000,000 pixels of the feature that subject is trickleer) can tackling high pixel.

In order to obtain the image of high image quality, all aberrations from wide-angle side to telescope end must be corrected well.But, if want the large aperture ratioization by existing techniques in realizing zoom lens, then can not correct all aberrations occurred in whole zoom territories well, be difficult to throughout full zoom territory and maintain high optical property.In addition, the image become clear can not be obtained in full zoom territory.

So, in the prior art headed by the zoom lens described in above-mentioned each patent documentation, can not realize the CCTV camera particularly for the purpose of the supervision in night and dim place the zoom lens that are applicable to.

Summary of the invention

The present invention its object is to, in order to eliminate the problem points of above-mentioned prior art, a kind of zoom lens of small-sized, light weight are provided, it can obtain the image become clear in full zoom territory, and by effectively correcting all aberrations throughout full zoom territory, maintain high optical property, possess the resolution of the solid-state imager can tackling high pixel.

In order to solve above-mentioned problem, reach object, zoom lens of the present invention, it is characterized in that, possess: configure in turn from object side, there is the first lens group of positive light coke, there is the second lens group of negative power, there is the 3rd lens group of positive light coke, there is the 4th lens group of positive light coke, there is the 5th lens group of negative power, and, described 5th lens group possesses: configure in turn from object side, there are the first lens of negative power, there is positive light coke and be at least formed with aspheric second lens in one side, by by described first lens group, described 3rd lens group and described 5th lens group are fixed, described second lens group is moved along optical axis from object side to image planes side, thus the zoom of carrying out from wide-angle side to telescope end, move along optical axis by making described 4th lens group, carry out the correction that changes with the image planes of zoom and focusing, and meet conditional shown below.

(1)0.7<|f52／F5|<2.5

(2)0.2<|rp／f51|<0.6

Wherein, f52 represents the focal length of the second lens of described 5th lens group, and F5 represents the focal length of described 5th lens group, and rp represents the radius-of-curvature in the face, image side of the first lens of described 5th lens group, and f51 represents the focal length of the first lens of described 5th lens group.

According to the present invention, can provide a kind of zoom lens of small-sized, light weight, it can obtain the image become clear in full zoom territory, and by effectively correcting all aberrations throughout full zoom territory, thus maintenance high optical property, possess the resolution of the solid-state imager can tackling high pixel.

Zoom lens of the present invention, is characterized in that, in described invention, meet conditional shown below.

(3) nd51 mono-nd52<0

Wherein, nd51 represents the refractive index to d line of the first lens of described 5th lens group, and nd52 represents the refractive index to d line of the second lens of described 5th lens group.

According to the present invention, can effectively correct all aberrations, maintain high optical property.

Zoom lens of the present invention, it is characterized in that, in described invention, described 5th lens group by configure in turn from object side, make to form convex surface facing first lens with the meniscus shape of negative power of object side and this two panels simple lens of the second lens with positive light coke.

According to the present invention, rear lens diameter can be reduced, realize small-sized, the lightweight of zoom lens complete set.

According to the present invention, the effect played is, can provide a kind of small-sized, the zoom lens of light weight, it can obtain the image become clear in full zoom territory, and by effectively correcting all aberrations throughout full zoom territory, maintaining high optical property, possessing the resolution of the solid-state imager can tackling high pixel.

Accompanying drawing explanation

Fig. 1 is the sectional view along optical axis of the formation of the zoom lens representing embodiment 1.

Fig. 2 is all aberration diagrams to d line of the zoom lens of embodiment 1.

Fig. 3 is the sectional view along optical axis of the formation of the zoom lens representing embodiment 2.

Fig. 4 is all aberration diagrams to d line of the zoom lens of embodiment 2.

Fig. 5 is the sectional view along optical axis of the formation of the zoom lens representing embodiment 3.

Fig. 6 is all aberration diagrams to d line of the zoom lens of embodiment 3.

Fig. 7 is the sectional view along optical axis of the formation of the zoom lens representing embodiment 4.

Fig. 8 is all aberration diagrams to d line of the zoom lens of embodiment 4.

Embodiment

Below, zoom lens of the present invention are explained preferred embodiment.

Zoom lens of the present invention possess: configure in turn from object side, first lens group with positive light coke, second lens group with negative power, have positive light coke the 3rd lens group, have positive light coke the 4th lens group, have negative power the 5th lens group and form.In these zoom lens, by the first lens group, the 3rd lens group and the 5th lens group being fixed, the second lens group is made to move to image planes side along optical axis from object side and carry out the zoom from wide-angle side to telescope end.In addition, by making the 4th lens group move along optical axis, carry out the correction that changes with the image planes of zoom and focusing.

The present invention its object is to, and provides a kind of small-sized, the zoom lens of light weight, it can obtain the image become clear in full zoom territory, and effectively correct all aberrations throughout full zoom territory, thus maintain high optical property, possess the resolution of the solid-state imager can tackling high pixel.In order to reach this purpose, and set various conditions so shown below.

First, in zoom lens of the present invention, the 5th lens group configures, has the first lens of negative power in turn and has positive light coke and be at least formed with aspheric second lens in one side and form from object side.

In the second lens forming aspheric surface of the 5th lens group, can correct well with large aperture ratioization and become significant astigmatism and curvature of the image in full zoom territory.Thus, because good aberration correction can be carried out with the lens of little sheet number, so can realize the lightweight of zoom lens.

And, in zoom lens of the present invention, by the focal length of the second lens of the 5th lens group for establishing f52, the focal length of the 5th lens group is set to F5, the radius-of-curvature in the face, image side of the first lens of the 5th lens group is set to rp, when the focal length of the first lens of the 5th lens group is set to f51, preferably meet following conditional.

(1)0.7<|f52／F5|<2.5

(2)0.2<|rp／f51|<0.6

Conditional (1) defines the appropriate scope of the ratio of the focal distance f 52 of the second lens of the 5th lens group in zoom lens of the present invention and the focal length F5 of the 5th lens group.

In conditional (1), if lower than its lower limit, then the second power of lens of the 5th lens group become too strong, the correction difficulty of astigmatism and curvature of the image.On the other hand, in conditional (1), if exceed its upper limit, then the second power of lens of the 5th lens group became weak, and the focal power of the 5th lens group entirety become too strong.Consequently, exit pupil position closely image planes.If exit pupil position is too close to image planes, then the size due to solid-state imager is certain, so the peripheral light amount ratio of output image (deep or light: シエ mono-ディ Application ゲ) worsens.

Conditional (2) is the formula of the shape in the face, image side of first lens leaning on object side to configure most of regulation the 5th lens group.In the present invention, in the face, image side of these the first lens, be formed with the large concave surface of curvature to correct all aberrations well.Therefore, by the formula of satisfying condition (2), the concave surface that the face, image side of these the first lens can be made to be formed and entrance pupil become concentric shape, can suppress the generation of all aberrations, maintain high optical property.

In conditional (2), if lower than its lower limit, the paraxial radius-of-curvature in the face, image side of the first lens of the 5th lens group becomes too small, and the processability of these the first lens worsens.If the processability of lens worsens, then the manufacturing cost of zoom lens improves, and is not therefore preferred.On the other hand, in conditional (2), if exceed its upper limit, although then the processability of the first lens becomes good, but the proper alignment of the concave surface formed in the face, image side of these the first lens and entrance pupil is destroyed, the correction of all aberrations is caused to become difficulty, optical performance degradation thus.

In addition, in zoom lens of the present invention, the first lens of the 5th lens group are set to nd51 to the refractive index of d line, when the refractive index to d line of the second lens of the 5th lens group is nd52, preferably meet following conditional.

(3)nd51-nd52<0

The suitable scope of the negative lens (the first lens) in conditional (3) regulation the 5th lens group and the specific refractivity to d line of positive lens (the second lens).By the formula of satisfying condition (3), the Po Zi of the 5th lens group entirety cuts down and becomes appropriate value, can maintain high optical property.In conditional (3), if lower than its lower limit, then the Po Zi of the 5th lens group entirety cuts down and becomes large, and the correction of all aberrations becomes difficulty.

In addition, in zoom lens of the present invention, preferably the 5th lens group by configure in turn from object side, make to form convex surface facing first lens with the meniscus shape of negative power of object side and this two panels simple lens of the second lens with positive light coke.So form the 5th lens group by 2 simple lenses, make the simplification of the 5th lens and lightweight become possibility.In addition, according to this formation, the rear lens diameter of optical system can be reduced, small-sized, the lightweight of zoom lens complete set can be realized.

As described above, zoom lens of the present invention, by possessing above-mentioned formation, the image become clear can be obtained in full zoom territory, and can effectively correct all aberrations throughout full zoom territory, thus maintenance high optical property, and can possess can be corresponding with the solid-state imager of high pixel resolution.

Particularly on the second lens of the 5th lens group, form aspheric surface, and meet above-mentioned conditional (1), the focal length of the second lens of the 5th lens group and the ratio optimization of the focal length of the 5th lens group can be made, correct with large aperture ratioization well and become significant astigmatism and curvature of the image in full zoom territory.In addition, by meeting above-mentioned conditional (2), the shape in the face, image side of first lens leaning on object side to configure most of the 5th lens group and entrance pupil can be made to be concentric shape, thus the generation of all aberrations can be suppressed, maintaining high optical property.And by meeting above-mentioned conditional (3), the Po Zi of the 5th lens group entirety cuts down and reaches appropriate value, can maintain high optical property.

Below, the embodiment of zoom lens of the present invention is explained based on accompanying drawing.Further, the present invention does not limit by following embodiment.

[embodiment 1]

Fig. 1 is the sectional view along optical axis of the formation of the zoom lens representing embodiment 1.The never illustrated object side of these zoom lens is configured with the first lens group G with positive light coke in turn ₁₁, there is the second lens group G of negative power ₁₂, there is the 3rd lens group G of positive light coke ₁₃, there is the 4th lens group G of positive light coke ₁₄, there is the 5th lens group G of negative power ₁₅and form.

At the second lens group G ₁₂with the 3rd lens group G ₁₃between, be configured with the aperture diaphragm STP defining set aperture.In addition, at the 5th lens group G ₁₅and between image planes IMG, be configured with cover glass CG.Further, the light receiving surface of solid-state imager is configured with at image planes IMG.

With regard to the first lens group G ₁₁, be configured with negative lens L in turn from object side ₁₁₁, positive lens L ₁₁₂, positive lens L ₁₁₃and form.Negative lens L ₁₁₁with positive lens L ₁₁₂engaged.

With regard to the second lens group G ₁₂, be configured with negative lens L in turn from object side ₁₂₁, negative lens L ₁₂₂, positive lens L ₁₂₃and form.Negative lens L ₁₂₂with positive lens L ₁₂₃engaged.

With regard to the 3rd lens group G ₁₃, be configured with positive lens L in turn from object side ₁₃₁with negative lens L ₁₃₂and form.At positive lens L ₁₃₁two sides formed aspheric surface.

With regard to the 4th lens group G ₁₄, be configured with positive lens L in turn from object side ₁₄₁with negative lens L ₁₄₂and form.At positive lens L ₁₄₁object side be formed with aspheric surface.In addition, positive lens L ₁₄₁with negative lens L ₁₄₂engaged.

With regard to the 5th lens group G ₁₅, be configured with negative lens L in turn from object side ₁₅₁(the first lens) and positive lens L ₁₅₂(the second lens) these 2 simple lenses and forming.Negative lens L ₁₅₁be made up of the negative meniscus lens made convex surface facing object side.In addition, at positive lens L ₁₅₂two sides be formed with aspheric surface.

In these zoom lens, the first lens group G ₁₁, aperture diaphragm STP, the 3rd lens group G ₁₃with the 5th lens group G ₁₅all the time be fixed.But, by making the second lens group G ₁₂move to image planes side along optical axis from object side and carry out the zoom from wide-angle side to telescope end.In addition, by making the 4th lens group G ₁₄move along optical axis, thus carry out correction and the focusing of the image planes variation come with zoom.

Below, the various numeric datas of the zoom lens about embodiment 1 are shown.

Focal length=15.0 (wide-angle side) ~ 27.4 (centre position) ~ 50.0 (telescope end) of zoom lens complete set

F number (Fno.)=1.41 (wide-angle side) ~ 1.41 (centre position) ~ 1.41 (telescope end)

Angle of half field-of view (ω)=17.31 (wide-angle side) ~ 9.28 (centre position) ~ 5.00 (telescope end)

(lens data)

r ₁＝52.701

d ₁＝1.00nd ₁＝1.84666vd ₁＝23.78

r ₂＝37.494

d ₂＝5.45nd ₂＝1.49700vd ₂＝81.54

r ₃＝-209.348

d ₃＝0.15

r ₄＝46.627

d ₄＝2.98nd ₃＝1.61800vd ₃＝63.39

r ₅＝173.394

D ₅=D (5) (variable)

r ₆＝-95.368

d ₆＝0.70nd ₄＝1.90366vd ₄＝31.31

r ₇＝21.124

d ₇＝2.76

r ₈＝-25.242

d ₈＝0.60nd ₅＝1.51633vd ₅＝64.14

r ₉＝24.624

d ₉＝1.90nd ₆＝1.95906vd ₆＝17.47

r ₁₀＝163.058

D ₁₀=D (10) (variable)

R ₁₁=∞ (aperture diaphragm)

d ₁₁＝0.80

R ₁₂=15.000 (aspheric surfaces)

d ₁₂＝3.80nd ₇＝1.59201vd ₇＝67.02

R ₁₃=-162.259 (aspheric surfaces)

d ₁₃＝5.82

r ₁₄＝57.534

d ₁₄＝0.80nd ₈＝1.92286vd ₈＝18.90

r ₁₅＝21.153

D ₁₅=D (15) (variable)

R ₁₆=15.452 (aspheric surfaces)

d ₁₆＝4.30nd ₉＝1.76802vd ₉＝49.24

r ₁₇＝-21.694

d ₁₇＝0.60nd ₁₀＝1.72825vd ₁₀＝28.32

r ₁₈＝-77.352

D ₁₈=D (18) (variable)

r ₁₉＝11.752

d ₁₉＝1.90nd ₁₁＝1.74077vd ₁₁＝27.76

r ₂₀＝6.977

d ₂₀＝1.77

R ₂₁=15.882 (aspheric surfaces)

d ₂₁＝2.20nd ₁₂＝1.82115vd ₁₂＝24.06

R ₂₂=23.347 (aspheric surfaces)

d ₂₂＝1.00

r ₂₃＝∞

d ₂₃＝2.50nd ₁₃＝1.51633vd ₁₃＝64.14

r ₂₄＝∞

d ₂₄＝4.64

R ₂₅=∞ (image planes)

Circular cone coefficient (k) and asphericity coefficient (A, B, C, D)

(the 12nd face)

k＝-0.5866，

A＝-3.61877×10 ^-6，B＝-7.61256×10 ^-8，

C＝3.33045×10 ^-10，D＝-6.25838×10 ^-12

(the 13rd face)

k＝83.9072，

A＝1.65979×10 ^-5，B＝-7.39338×10 ^-8，

C＝-3.64627×10 ^-11，D＝-2.87932×10 ^-12

(the 16th face)

k＝-1.3890，

A＝-1.59736×10 ^-5，B＝1.27294×10 ^-7，

C＝-4.84226×10 ^-9，D＝4.27025×10 ^-11

(the 21st face)

k＝2.8196，

A＝-1.79940×10 ^-5，B＝-2.89823×10 ^-6，

C＝7.03458×10 ^-8，D＝-5.72816×10 ^-9

(the 22nd face)

k＝2.8897，

A＝-9.52100×10 ^-6，B＝1.32989×10 ^-6，

C＝-2.79234×10 ^-7，D＝-8.90638×10 ^-10

(zoom data)

(numerical value about conditional (1))

F52 (positive lens L ₁₅₂the focal length of (the second lens))=53.396

F5 (the 5th lens group G ₁₅focal length)=-53.396

|f52/F5|＝1

(numerical value about conditional (2))

Rp (negative lens L ₁₅₁the radius-of-curvature in the face, image side of (the first lens))=6.977

F51 (negative lens L ₁₅₁the focal length of (the first lens))=-27.909

|rp/f51|＝0.25

(numerical value about conditional (3))

Nd51 (negative lens L ₁₅₁the refractive index to d line of (the first lens))=1.74077

Nd52 (positive lens L ₁₅₂the refractive index to d line of (the second lens))=1.82115

nd51-nd52＝-0.08

Fig. 2 is all aberration diagrams to d line (λ=587.56nn) of the zoom lens of embodiment 1.Further, S, M in astigmatism figure represent the aberration corresponding to sagittal image surface, meridianal image surface respectively.

[embodiment 2]

Fig. 3 is the sectional view along optical axis of the formation of the zoom lens representing embodiment 2.The never illustrated object side of these zoom lens configures the first lens group G with positive light coke in turn ₂₁, there is the second lens group G of negative power ₂₂, there is the 3rd lens group G of positive light coke ₂₃, there is the 4th lens group G of positive light coke ₂₄, there is the 5th lens group G of negative power ₂₅and form.

At the second lens group G ₂₂with the 3rd lens group G ₂₃between, be configured with the aperture diaphragm STP defining set aperture.In addition, at the 5th lens group G ₂₅and between image planes IMG, be configured with cover glass CG.Further, the light receiving surface of solid-state imager is configured with at image planes IMG.

With regard to the first lens group G ₂₁, be configured with negative lens L in turn from object side ₂₁₁, positive lens L ₂₁₂, positive lens L ₂₁₃and form.Negative lens L ₂₁₁with positive lens L ₂₁₂engaged.

With regard to the second lens group G ₂₂, be configured with negative lens L in turn from object side ₂₂₁, negative lens L ₂₂₂, positive lens L ₂₂₃and form.Negative lens L ₂₂₂with positive lens L ₂₂₃engaged.

With regard to the 3rd lens group G ₂₃, be configured with positive lens L in turn from object side ₂₃₁, negative lens L ₂₃₂and form.At positive lens L ₂₃₁two sides be formed with aspheric surface.

With regard to the 4th lens group G ₂₄, be configured with positive lens L in turn from object side ₂₄₁, negative lens L ₂₄₂and form.At positive lens L ₂₄₁object side be formed with aspheric surface.In addition, positive lens L ₂₄₁with negative lens L ₂₄₂engaged.

With regard to the 5th lens group G ₂₅, be configured with negative lens L in turn from object side ₂₅₁(the first lens) and positive lens L ₂₅₂(the second lens) these 2 simple lenses and forming.Negative lens L ₂₅₁be made up of the negative meniscus lens made convex surface facing object side.In addition, at positive lens L ₂₅₂two sides be formed with aspheric surface.

In these zoom lens, the first lens group G ₂₁, aperture diaphragm STP, the 3rd lens group G ₂₃with the 5th lens group G ₂₅all the time be fixed.But, by making the second lens group G ₂₂move to image planes side along optical axis from object side and carry out the zoom from wide-angle side to telescope end.In addition, by making the 4th lens group G ₂₄move along optical axis, carry out the correction that changes along with the image planes of zoom and focusing.

Below, the various numeric datas of the zoom lens about embodiment 2 are shown.

F number (Fno.)=1.42 (wide-angle side) ~ 1.44 (centre position) ~ 1.44 (telescope end)

Angle of half field-of view (ω)=17.19 (wide-angle side) ~ 9.23 (centre position) ~ 5.00 (telescope end)

(lens data)

r ₁＝57.066

d ₁＝1.00nd ₁＝1.84666vd ₁＝23.78

r ₂＝39.550

d ₂＝5.11nd ₂＝1.49700vd ₂＝81.54

r ₃＝-245.030

d ₃＝0.15

r ₄＝48.097

d ₄＝3.05nd ₃＝1.61800vd ₃＝63.39

r ₅＝222.471

D ₅=D (5) (variable)

r ₆＝-143.269

d ₆＝0.70nd ₄＝1.90366vd ₄＝31.31

r ₇＝20.787

d ₇＝3.02

r ₈＝-22.781

d ₈＝0.60nd ₅＝1.51633vd ₅＝64.14

r ₉＝27.841

d ₉＝1.90nd ₆＝1.95906vd ₆＝17.47

r ₁₀＝486.697

D ₁₀=D (10) (variable)

R ₁₁=∞ (aperture diaphragm)

d ₁₁＝0.80

R ₁₂=15.214 (aspheric surfaces)

d ₁₂＝3.80nd ₇＝1.61881vd ₇＝63.85

R ₁₃=-300.983 (aspheric surfaces)

d ₁₃＝5.32

r ₁₄＝70.442

d ₁₄＝0.80nd ₈＝1.92286vd ₈＝18.90

r ₁₅＝21.752

D ₁₅=D (15) (variable)

R ₁₆=13.489 (aspheric surfaces)

d ₁₆＝4.30nd ₉＝1.76802vd ₉＝49.24

r ₁₇＝-25.255

d ₁₇＝0.60nd ₁₀＝1.72825vd ₁₀＝28.32

r ₁₈＝-49.793

D ₁₈=D (18) (variable)

r ₁₉＝17.183

d ₁₉＝1.90nd ₁₁＝1.74077vd ₁₁＝27.76

r ₂₀＝7.215

d ₂₀＝1.76

R ₂₁=17.712 (aspheric surfaces)

d ₂₁＝2.20nd ₁₂＝1.82115vd ₁₂＝24.06

R ₂₂=31.109 (aspheric surfaces)

d ₂₂＝1.00

r ₂₃＝∞

d ₂₃＝2.50nd ₁₃＝1.51633vd ₁₃＝64.14

r ₂₄＝∞

d ₂₄＝5.58

R ₂₅=∞ (image planes)

Circular cone coefficient (k) and asphericity coefficient (A, B, C, D)

(the 12nd face)

k＝-0.6090，

A＝-4.19699×10 ^-6，B＝-9.56196×10 ^-8，

C＝6.43385×10 ^-10，D＝-8.48882×10 ^-12

(the 13rd face)

k＝13.6295，

A＝4.91055×10 ^-6，B＝-2.78020×10 ^-8，

C＝-4.26331×10 ^-11，D＝-3.78172×10 ^-12

(the 16th face)

k＝-1.4320，

A＝-1.94318×10 ^-5，B＝2.72495×10 ^-8，

C＝-3.03937×10 ^-9，D＝3.38298×10 ^-11

(the 21st face)

k＝3.3539，

A＝-2.50356×10 ^-5，B＝4.03139×10 ^-7，

C＝-2.52553×10 ^-8，D＝-4.37056×10 ^-9

(the 22nd face)

k＝4.9321，

A＝-3.78714×10 ^-6，B＝3.63191×10 ^-6，

C＝-2.99492×10 ^-7，D＝-5.48636×10 ^-10

(zoom data)

(numerical value about conditional (1))

F52 (positive lens L ₂₅₂the focal length of (the second lens))=46.436

F5 (the 5th lens group G ₂₅focal length)=-29.437

|f52／F5|＝1.578

(numerical value about conditional (2))

Rp (negative lens L ₂₅₁the radius-of-curvature in the face, image side of (the first lens))=6.215

F51 (negative lens L ₂₅₁the focal length of (the first lens))=-18.274

|rp／f51|＝0.34

(numerical value about conditional (3))

Nd51 (negative lens L ₂₅₁the refractive index to d line of (the first lens))=1.74077

Nd52 (positive lens L ₂₅₂the refractive index to d line of (the second lens))=1.82115

nd51-nd52＝-0.08

Fig. 4 is all aberration diagrams to d line (λ=587.56nn) of the zoom lens of embodiment 2.Further, S, M in astigmatism figure represent the aberration corresponding to sagittal image surface, meridianal image surface respectively.

[embodiment 3]

Fig. 5 is the sectional view along optical axis of the formation of the zoom lens representing embodiment 3.The never illustrated object side of these zoom lens configures the first lens group G with positive light coke in turn ₃₁, there is the second lens group G of negative power ₃₂, there is the 3rd lens group G of positive light coke ₃₃, there is positive light coke the 4th lens group G ₃₄, there is the 5th lens group G of negative power ₃₅and form.

At the second lens group G ₃₂with the 3rd lens group G ₃₃between, be configured with the aperture diaphragm STP defining set aperture.In addition, at the 5th lens group G ₃₅and between image planes IMG, be configured with cover glass CG.Further, the light receiving surface of solid-state imager is configured with at image planes IMG.

With regard to the first lens group G ₃₁, be configured with negative lens L in turn from object side ₃₁₁, positive lens L ₃₁₂, positive lens L ₃₁₃and form.Negative lens L ₃₁₁with positive lens L ₃₁₂engaged.

With regard to the second lens group G ₃₂, be configured with negative lens L in turn from object side ₃₂₁, negative lens L ₃₂₂, positive lens L ₃₂₃and form.Negative lens L ₃₂₂with positive lens L ₃₂₃engaged.

With regard to the 3rd lens group G ₃₃, be configured with positive lens L in turn from object side ₃₃₁, negative lens L ₃₃₂and form.At positive lens L ₃₃₁two sides be formed with aspheric surface.

With regard to the 4th lens group G ₃₄, be configured with positive lens L in turn from object side ₃₄₁with negative lens L ₃₄₂and form.At positive lens L ₃₄₁object side formed aspheric surface.In addition, positive lens L ₃₄₁with negative lens L ₃₄₂engaged.

With regard to the 5th lens group G ₃₅, be configured with negative lens L in turn from object side ₃₅₁(the first lens) and positive lens L ₃₅₂(the second lens) these 2 simple lenses and forming.Negative lens L ₃₅₁be made up of the negative meniscus lens convex surface facing object side.In addition, at positive lens L ₃₅₂two sides be formed with aspheric surface.

In these zoom lens, the first lens group G ₃₁, aperture diaphragm STP, the 3rd lens group G ₃₃with the 5th lens group G ₃₅be fixed.But, by making the second lens group G ₃₂move to image planes side along optical axis from object side and carry out the zoom from wide-angle side to telescope end.In addition, by making the 4th lens group G ₃₄move along optical axis, carry out the correction that changes with the image planes of zoom and focusing.

Below, the various numeric datas of the zoom lens about embodiment 3 are shown.

Focal length=15.0 (wide-angle side) ~ 274 (centre position) ~ 50.0 (telescope end) of zoom lens complete set

Angle of half field-of view (ω)=17.15 (wide-angle side) ~ 9.22 (centre position) ~ 5.00 (telescope end)

(lens data)

r ₁＝55.770

d ₁＝1.00nd ₁＝1.84666vd ₁＝23.78

r ₂＝39.896

d ₂＝5.06nd ₂＝1.49700vd ₂＝81.54

r ₃＝-197.191

d ₃＝0.15

r ₄＝47.173

d ₄＝2.70nd ₃＝1.61800vd ₃＝63.39

r ₅＝132.026

D ₅=D (5) (variable)

r ₆＝205.465

d ₆＝0.70nd ₄＝1.90366vd ₄＝31.31

r ₇＝19.963

d ₇＝3.80

r ₈＝-19.359

d ₈＝0.60nd ₅＝1.51633vd ₅＝64.14

r ₉＝35.304

d ₉＝1.90nd ₆＝1.95906vd ₆＝17.47

r ₁₀＝-414.596

D ₁₀=D (10) (variable)

R ₁₁=∞ (aperture diaphragm)

d ₁₁＝0.80

R ₁₂=16.621 (aspheric surfaces)

d ₁₂＝3.80nd ₇＝1.61881vd ₇＝63.85

R ₁₃=-115.603 (aspheric surfaces)

d ₁₃＝435

r ₁₄＝69.820

d ₁₄＝0.80nd ₈＝1.92286vd ₈＝18.90

r ₁₅＝21.887

D ₁₅=D (15) (variable)

R ₁₆=14.112 (aspheric surfaces)

d ₁₆＝430nd ₉＝1.76802vd ₉＝49.24

r ₁₇＝-23.853

d ₁₇＝0.60nd ₁₀＝1.72825vd ₁₀＝28.32

r ₁₈＝-43.429

D ₁₈=D (18) (variable)

r ₁₉＝20.742

d ₁₉＝1.90nd ₁₁＝1.71736vd ₁₁＝29.50

r ₂₀＝6.937

d ₂₀＝1.71

R ₂₁=16.656 (aspheric surfaces)

d ₂₁＝2.20nd ₁₂＝1.82115vd ₁₂＝24.06

R ₂₂=38.845 (aspheric surfaces)

d ₂₂＝1.00

r ₂₃＝∞

d ₂₃＝2.50nd ₁₃＝1.51633vd ₁₃＝64.14

r ₂₄＝∞

d ₂₄＝6.16

R ₂₅=∞ (image planes)

Circular cone coefficient (k) and asphericity coefficient (A, B, C, D)

(the 12nd face)

k＝-0.5439，

A＝-1.48046×10 ^-6，B＝-6.19350×10 ^-8，

C＝3.86077×10 ^-10，D＝-5.71423×10 ^-12

(the 13rd face)

k＝-0.2573，

A＝1.81004×10 ^-5，B＝-2.58080×10 ^-8，

C＝1.42210×10 ^-10，D＝-3.82567×10 ^-12

(the 16th face)

k＝-1.3867，

A＝-1.71342×10 ^-5，B＝1.81833×10 ^-8，

C＝-1.77195×10 ^-9，D＝1.91952×10 ^-11

(the 21st face)

k＝4.4474，

A＝2.05738×10 ^-5，B＝-1.83122×10 ^-8，

C＝5.50981×10 ^-8，D＝-6.10561×10 ^-9

(the 22nd face)

k＝24.9779，

A＝4.51606×10 ^-5，B＝-1.43913×10 ^-7，

C＝-1.36900×10 ^-7，D＝-4.15559×10 ^-9

(zoom data)

(numerical value about conditional (1))

F52 (positive lens L ₃₅₂the focal length of (the second lens))=35.284

F5 (the 5th lens group G ₃₅focal length)=-27.614

|f52／F5|＝1.278

(numerical value about conditional (2))

Rp (negative lens L ₃₅₁the radius-of-curvature in the face, image side of (the first lens))=6.937

F51 (negative lens L ₃₅₁the focal length of (the first lens))=-15415

|rp／f51|＝0.45

(numerical value about conditional (3))

Nd51 (negative lens L ₃₅₁the refractive index to d line of (the first lens))=1.71736

Nd52 (positive lens L ₃₅₂the refractive index to d line of (the second lens))=1.82115

nd51-nd52＝-0.104

Fig. 6 is all aberration diagrams to d line (λ=587.56nn) of the zoom lens of embodiment 3.Further, S, M in astigmatism figure represent the aberration corresponding to sagittal image surface, meridianal image surface respectively.

[embodiment 4]

Fig. 7 is the sectional view along optical axis of the formation of the zoom lens representing embodiment 4.The never illustrated object side of these zoom lens configures the first lens group G with positive light coke in turn ₄₁, there is the second lens group G of negative power ₄₂, there is the 3rd lens group G of positive light coke ₄₃, there is the 4th lens group G of positive light coke ₄₄, there is the 5th lens group G of negative power ₄₅and form.

At the second lens group G ₄₂with the 3rd lens group G ₄₃between, be configured with the aperture diaphragm STP defining set aperture.In addition, at the 5th lens group G ₄₅and between image planes IMG, be configured with cover glass CG.Further, the light receiving surface of solid-state imager is configured with at image planes IMG.

With regard to the first lens group G ₄₁, be configured with negative lens L in turn from object side ₄₁₁, positive lens L ₄₁₂, positive lens L ₄₁₃and form.Negative lens L ₄₁₁with positive lens L ₄₁₂engaged.

With regard to the second lens group G ₄₂, be configured with negative lens L in turn from object side ₄₂₁, negative lens L ₄₂₂, positive lens L ₄₂₃and form.Negative lens L ₄₂₂with positive lens L ₄₂₃engaged.

With regard to the 3rd lens group G ₄₃, be configured with positive lens L in turn from object side ₄₃₁, negative lens L ₄₃₂and form.At positive lens L ₄₃₁two sides be formed with aspheric surface.

With regard to the 4th lens group G ₄₄, be configured with positive lens L in turn from object side ₄₄₁, negative lens L ₄₄₂and form.At positive lens L ₄₄₁object side be formed with aspheric surface.In addition, positive lens L ₄₄₁with negative lens L ₄₄₂engaged.

With regard to the 5th lens group G ₄₅, be configured with negative lens L in turn from object side ₄₅₁(the first lens) and positive lens L ₄₅₂(the second lens) these 2 simple lenses and forming.Negative lens L ₄₅₁be made up of the negative meniscus lens made convex surface facing object side.In addition, at positive lens L ₄₅₂two sides be formed with aspheric surface.

In these zoom lens, the first lens group G ₄₁, aperture diaphragm STP, the 3rd lens group G ₄₃with the 5th lens group G ₄₅be fixed.But, by making the second lens group G ₄₂move to image planes side along optical axis from object side and carry out the zoom from wide-angle side to telescope end.In addition, by making the 4th lens group G ₄₄move along optical axis, carry out the correction that changes with the image planes of zoom and focusing.

Below, the various numeric datas of the zoom lens about embodiment 4 are shown.

Angle of half field-of view (ω)=17.15 (wide-angle side) ~ 9.21 (centre position) ~ 5.00 (telescope end)

(lens data)

r ₁＝64.654

d ₁＝1.00nd ₁＝1.84666vd ₁＝23.78

r ₂＝42.859

d ₂＝4.83nd ₂＝1.49700vd ₂＝81.54

r ₃＝-188.181

d ₃＝0.15

r ₄＝46.926

d ₄＝3.02nd ₃＝1.61800vd ₃＝63.39

r ₅＝214.595

D ₅=D (5) (variable)

r ₆＝-159.632

d ₆＝0.70nd ₄＝1.90366vd ₄＝31.31

r ₇＝21.034

d ₇＝3.04

r ₈＝-22.653

d ₈＝0.60nd ₅＝1.51633vd ₅＝64.14

r ₉＝28.525

d ₉＝1.90nd ₆＝1.95906vd ₆＝17.47

r ₁₀＝619.032

D ₁₀=D (10) (variable)

R ₁₁=∞ (aperture diaphragm)

d ₁₁＝0.80

R ₁₂=15.492 (aspheric surfaces)

d ₁₂＝3.80nd ₇＝1.61881vd ₇＝63.85

R ₁₃=461.986 (aspheric surfaces)

d ₁₃＝4.96

r ₁₄＝64.368

d ₁₄＝0.80nd ₈＝1.95906vd ₈＝17.47

r ₁₅＝25.648

D ₁₅=D (15) (variable)

R ₁₆=13.369 (aspheric surfaces)

d ₁₆＝4.30nd ₉＝1.76802vd ₉＝49.24

r ₁₇＝-25.681

d ₁₇＝0.60nd ₁₀＝1.72825vd ₁₀＝28.32

r ₁₈＝-49.936

D ₁₈=D (18) (variable)

r ₁₉＝21.590

d ₁₉＝1.90nd ₁₁＝1.74077vd ₁₁＝27.76

r ₂₀＝7.666

d ₂₀＝1.63

R ₂₁=22.153 (aspheric surfaces)

d ₂₁＝2.20nd ₁₂＝1.82115vd ₁₂＝24.06

R ₂₂=45.276 (aspheric surfaces)

d ₂₂＝1.00

r ₂₃＝∞

d ₂₃＝2.50nd ₁₃＝1.51633vd ₁₃＝64.14

r ₂₄＝∞

d ₂₄＝6.63

R ₂₅=∞ (image planes)

Circular cone coefficient (k) and asphericity coefficient (A, B, C, D)

(the 12nd face)

k＝-0.6311，

A=-4.15876×10 ^-6，B=-1.37883×10 ^-7，

C＝4.15271×10 ^-10，D＝-1.52593×10 ^-11

(the 13rd face)

k＝-100.0000，

A＝-3.24557×10 ^-6，B＝-3.64173×10 ^-8，

C＝-7.92874×10 ^-10，D＝-5.83352×10 ^-12

(the 16th face)

k＝-1.4459，

A＝-2.09475×10 ^-5，B＝-8.45495×10 ^-8，

C＝-1.17046×10 ^-9，D＝2.39402×10 ^-11

(the 21st face)

k＝4.1333，

A＝5.12895×10 ^-5，B＝1.63393×10 ^-6，

C＝2.00177×10 ^-8，D＝-4.75306×10 ^-9

(the 22nd face)

k＝10.1512，

A＝9.62421×10 ^-5，B＝2.29371×10 ^-6，

C＝-7.74967×10 ^-8，D＝-4.41659×10 ^-9

(zoom data)

(numerical value about conditional (1))

F52 (positive lens L ₄₅₂the focal length of (the second lens))=50.65

F5 (the 5th lens group G ₄₅focal length)=-25.581

|f52／F5|＝1.98

(numerical value about conditional (2))

Rp (negative lens L ₄₅₁the radius-of-curvature in the face, image side of (the first lens))=7.666

F51 (negative lens L ₄₅₁the focal length of (the first lens))=-17.035

|rp/f51|＝0.45

(numerical value about conditional (3))

Nd51 (negative lens L ₄₅₁the refractive index to d line of (the first lens))=1.74077

Nd52 (positive lens L ₄₅₂the refractive index to d line of (the second lens))=1.82115

nd51-nd52＝-0.08

Fig. 8 is all aberration diagrams to d line (λ=587.56nn) of the zoom lens of embodiment 4.Further, S, M in astigmatism figure represent the aberration corresponding to sagittal image surface, meridianal image surface respectively.

Further, in the numeric data in the various embodiments described above, r ₁, r ₂... represent the radius-of-curvature in each lens, diaphragm face etc., d ₁, d ₂... represent wall thickness or its interval, face of each lens, diaphragm etc., nd ₁, nd ₂... represent the refractive index to d line (λ=587.56nm) of each lens, vd ₁, vd ₂... represent the Abbe number to d line (λ=587.56nm) of each lens.And the unit of length is all " mm ", the unit of angle is all " ° ".

In addition, above-mentioned each aspherical shape, the aspheric degree of depth is being set to Z, the height in the direction vertical with optical axis is set to y, paraxial radius-of-curvature is set to R, and circular cone coefficient is set to k, and the asphericity coefficient of 4 times, 6 times, 8 times, 10 times is set to A, B, C, D respectively, with the direct of travel of light for timing, represented by formula shown below.

[formula 1]

Z = \frac{y^{2}}{R {(1 + \sqrt{1 - (1 + k) y / R^{2}})}^{2}} + {Ay}^{4} + {By}^{6} + {Cy}^{8} + {Dy}^{10}

As described above, the zoom lens of the various embodiments described above, by possessing above-mentioned formation, the image become clear can be obtained in full zoom territory, and can effectively correct all aberrations throughout full zoom territory, thus maintenance high optical property, possess can be corresponding with the solid-state imager of high pixel resolution.Particularly by meeting above-mentioned each conditional, a kind of zoom lens of small-sized, light weight can be realized, its to be the F number crossing over full zoom territory be about 1.4 large aperture ratio, maintain again the high optical property that effectively can correct all aberrations throughout full zoom territory simultaneously, possess the high resolving power of the solid photographic element can tackling more than 3,000,000 pixels.

[utilizability in industry]

As above, zoom lens of the present invention, for monitoring that the CCTV camera at night and dim place is useful, no matter be most suitable for the traffic monitoring video camera all requiring the evidence image providing distinctness round the clock especially.

[symbol description]

G ₁₁, G ₂₁, G ₃₁, G ₄₁first lens group

G ₁₂, G ₂₂, G ₃₂, G ₄₂second lens group

G ₁₃, G ₂₃, G ₃₃, G ₄₃3rd lens group

G ₁₄, G ₂₄, G ₃₄, G ₄₄4th lens group

G ₁₅, G ₂₅, G ₃₅, G ₄₅5th lens group

L ₁₁₁, L ₁₂₁, L ₁₂₂, L ₁₃₂, L ₁₄₂, L ₁₅₁, L ₂₁₁, L ₂₂₁, L ₂₂₂, L ₂₃₂, L ₂₄₂, L ₂₅₁, L ₃₁₁, L ₃₂₁, L ₃₂₂, L ₃₃₂, L ₃₄₂, L ₃₅₁, L ₄₁₁, L ₄₂₁, L ₄₂₂, L ₄₃₂, L ₄ ₄₂, L ₄₅₁negative lens

L ₁₁₂, L ₁₁₃, L ₁₂₃, L ₁₃₁, L ₁₄₁, L ₁₅₂, L ₂₁₂, L ₂₁₃, L ₂₂₃, L ₂₃₁, L ₂₄₁, L ₂₅₂, L ₃₁₂, L ₃₁₃, L ₃₂₃, L ₃₃₁, L ₃₄₁, L ₃₅₂, L ₄₁₂, L ₄₁₃, L ₄₂₃, L ₄₃₁, L ₄ ₄₁, L ₄₅₂positive lens

STP aperture diaphragm

CG cover glass

IMG image planes

Claims

1. zoom lens, is characterized in that,

Possess: configure in turn from object side, first lens group with positive light coke, second lens group with negative power, have positive light coke the 3rd lens group, there is the 4th lens group of positive light coke, there is the 5th lens group of negative power,

Described 5th lens group possesses: configure in turn from object side, has the first lens of negative power, has positive light coke and is at least formed with aspheric second lens in one side,

Described first lens group, described 3rd lens group and described 5th lens group are fixed, the zoom from wide-angle side to telescope end is carried out by making described second lens group move along optical axis from object side to image planes side, move along optical axis by making described 4th lens group, carry out the correction that changes with the image planes of zoom and focusing

And meet conditional shown below,

(1)0.7＜|f52/F5|＜2.5

(2)0.2＜|rp/f51|＜0.6

(3)nd51-nd52＜0

Wherein, f52 represents the focal length of the second lens of described 5th lens group, F5 represents the focal length of described 5th lens group, rp represents the radius-of-curvature in the face, image side of the first lens of described 5th lens group, f51 represents the focal length of the first lens of described 5th lens group, nd51 represents the refractive index to d line of the first lens of described 5th lens group, and nd52 represents the refractive index to d line of the second lens of described 5th lens group.

2. zoom lens according to claim 1, is characterized in that,

Described 5th lens group by configure in turn from object side, make to form convex surface facing first lens with the meniscus shape of negative power of object side and these 2 simple lenses of the second lens with positive light coke.